Rangen ruling curtails Magic Valley well users

The Idaho Department of Water Resources has ruled the experimental trout farm Rangen, Inc., of Hagerman, should receive 9.1 cfs from Magic Valley groundwater irrigators. However, IDWR has also discovered Rangen has been drawing water from a point of diversion not specified in its water right.

Groundwater users covered by the ruling — those with rights junior to July 13, 1962 in parts of Cassia, Camas, Minidoka, Jerome, Lincoln, Blaine, Gooding and Twin Falls counties — will be allowed to gradually phase in their obligations over a five-year period.

The call, filed by Rangen, Inc., in response to years of declining spring flows due to groundwater wells, drought and more efficient irrigation practices, had previously been dismissed as futile because of the margin of error in IDWR’s water model, known by the acronym ESPAM 1.1. Rangen’s case was revived when IDWR issued a more precise model, ESPAM 2.1.

IDWR had been using a 10 percent “trim line,” excluding wells from calls if curtailment would deplete Rangen’s flows by less than 10 percent of a junior water right holder’s total consumption. Spackman’s ruling used a 1.5 percent trim line, noting the encompassed area has a relatively strong geologic tie to Rangen’s spring.

“The director finds, based upon clear and convincing evidence, that ESPAM 2.1 is the best technical scientific tool available to predict the effect of groundwater pumping on flows from springs located in the Rangen cell,” Spackman’s Jan. 29 curtailment order reads.

Rangen had requested that no trim line be applied, which would have broadened the call to 565,000 acres drawing from the aquifer as far north as Idaho Falls.

Rangen’s right specifies water must be diverted at the origin of its spring, called Curran Tunnel. However, IDWR Deputy Director Mat Weaver said staff discovered during the case review that Rangen operates a diversion downstream from the tunnel.

In response, IDWR has issued Rangen a cease and desist order, granting the business until Feb. 24 to either upgrade its infrastructure to draw only from Curran Tunnel or to refile its water right, which would give opponents a chance to file objections. Further complicating matters for Rangen, entities including Idaho Ground Water Appropriators filed in 2013 for rights to spring water that has thus far been put to use by the trout farm, though it emerges below Curran Tunnel.

Weaver believes the issue may give Rangen more incentive to settle with groundwater users, who would be asked to mitigate with 54-degree spring water equal to 3.4 cfs this year, 5.2 cfs in 2015, 6 cfs in 2016, 6.6 cfs in 2017 and 9.1 cfs from 2018 onward.

Surface Water Coalition attorney John Simpson explained his client intervened in the case in support of ESPAM 2.1 as “the best science available,” understanding the model will likely be used in delivery calls above Milner Dam.

Rangen Executive Vice President Wayne Courtney declined to comment, as he considers the case to still be pending. IGWA Executive Director Lynn Tominaga believes a 1.5 percent trim line is much too precise. If no settlement is reached, he intends to file for Spackman to reconsider or clarify the issue. If that fails, he’ll seek to have the case reconsidered in Idaho district court.